Refrigerant evaporator



L. (1.. SMITH REFRIGERANT EVAPORATOR July 16, 1940.

Filed Sept. 2, 1938 mwm w Us MC. a M

UNITED STATES PATENT OFFICE 2,208,169 REFBIGERAN '1 EVAPORATOR Lawrence C. Smith, Kenmore,

Fedders Manufacturing Company,

N. Y. Application September 2,

N. Y., assignor to Inc., Buffalo,

1938, Serial No. 228,131

4 Claims. (Cl. 62-426) This invention relates to improvements in evaporators used in refrigeration systems.

The invention is particularly applicable to smaller types of evaporators of the flooded type. In such units operating effectiveness is critically judged by uniform'ty of cooling temperature throughout the unit, and by the ability of the evaporator to maintain a relatively constant superheat at its suction outlet under the entire range of adjustment. Both of these features are desirable, first,

for sanitary reasons, and second, to insure quiet operation of the compressor,

and high efficiency of the entire system.

The present evaporator is devised to provide a manifolding system in which the liquid feed and gas exhaust follow two perfectly lines through a end that the communicating fed. The evaporator is also justable portion vary the elevation of the suction feature provides a valuable adjunct to symmetrical closed tubular header, to the ducts are equally formed with an adwhich is manually bendable to outlet. This the usual adjustable feed control of the evaporator, and it is disposed at a readily accessible point at the front of the evaporator where the service man may make a critical adjustment, often without altering the more complex feed control instrumentality.

The invention will also be found to reside in a tubular structure of ducts and header having a minimum number of joints and bends, and as a result presenting an effective mass production item. These and other features of the invention are more fully set forth in the accompanying specification and drawing, wherein:

Fig. 1 is a top v Fig. 2 is a side tion branch of on the line 2-2 0 The evaporator municating ducts iew of the evaporator; elevation thereof, with the sucthe header shown in section, taken f Fig. 1.

includes a header I0 and com- II, the latter of which may be formed in any desired manner, depending on the service in which the evaporator is employed. In

a small domestic refrigerator the ducts are formed as depending tube loops, as shown, to enclose and support a sleeve I2, which in turn is utilized as taining ice trays The header III a fast freezing chamber. for conor other vessels. is preferably formed of a single tube which is bent into rectangular formation to provide side portions I4, Ida, and front and rear portions I5 ll of the header tube are joined to form circuit; for example, the ends may a to a fitting I8 in and I6 respectively. The ends a closed be connected the rear portion I6.

Refrigerant from a controlled source is introrear portion I6 through a supply conduit 20. In the present instance, the centrallized location of the fitting I8 permits its continued use as a 5 coupling and an inlet fitting, and thus it is formed as a T for additional connection to the conduit 20. The center of the opposite or front portion I5 of the header communicates directly with the suction conduit 2| of the re- 10 frigeration system. The portion I5 is formed with a large centrallized loop 23 which is bent inward toward the rear section I6, and it will be observed that this structure leaves a large unobstructed area at the top front of the evaporator wherein the usual cold control unit 24 may be mounted, as indicated in dotted lines.

The header III is mounted horizontally and the ducts II depend vertically therefrom, the end Ila, Ilb of the ducts being entered and sol- 2o dered in suitably drilled holes in the side portions I4, Ila of the header.

In the operation of the evaporator the refrigerant enters the header laterally and splits into two streams flowing toward the side portions I4, Ila to supply the communicating ducts II. As 0 the refrigerant evaporates, the gaseous products are drawn off through the loop 23, where, due to the extra exposed surface of the loop, a secondary evaporation or drying takes place before introduction of the gas into the suction conduit 2 In order to prevent too ready an access of the liquid refrigerant to the suction conduit 2|, the loop 23 is bent upward above the level of the other portions of the evaporator so that the suction conduit communicates with a highpoint in the evaporator. With the use of modern supply controls in the inlet conduit 20, which may be a high side float or expansion valve (not shown), the liquid level in a header may be maintained at a predetermined level with a fair degree of accuracy. In Fig. 2, for example, a high liquid level is indicated by the letter L. In prior devices, any change of operating condition causing variation or raising or lowering of the liquid level, has demanded as a corrective delicate readjustment of the supply control device. In the present invention, the loop 23 offers a secondary adjustment, which in the majority of instances obviates the necessity of adjustment of the previously mentioned control. The structure and disposal of the loop is such that it may be bent to any degree of angularity relative to the horizontal portions of the header; for example as shown in Fig. 2, it may be bent from the position shown to that illustrated in dotted lines.

The crank-like loop portion 23 may thus be adjusted to elevate the suction outlet any desired distance above the liquid level, and, inasmuch as the portion 23 is located in the zone of the warmest air, it presents additional evaporative surface- The fabrication of joined tubular forms is presented to illustrate a simple and economical meth-- d of producing an evaporator. However, it will be understood that the general form and operating features of the evaporator are not limited to such specific structure, as they may be embodied in other manners without departing from the inventive concept, as set forth in the accompanying claims.

I claim:

1. In an evaporator, an elongated header having connected extremities to form a closed receptacle, said header being formed with a bendable section, a suction conduit communicating with said bendable section, a supply conduit communicating with a portion of the header sym-r metrically opposed to said bendable section, and a plurality of depending ducts connected to the header intermediate said section and said supply conduit.

2. In an evaporator, an elongated tubular header formed into rectangular shape and having connected extremities to provide a closed receptacle, a supply conduit communicating with the center of one side of the header, the opposing ceptacle,

side of the header being formed with a bendable loop portion extending toward said first side, a suction conduit communicating with the center of the loop portion, and a plurality of ducts communicating with. the remaining sides of the header.

3. In an evaporator, an elongated tubular header formed into rectangular shape and having connected extremities to provide a closed rea supply conduit communicating with the center of one side of the header, the opposing side of the header being formed with a loop portion extending toward said first side, a suction conduit communicating with said loop portion, a plurality of ducts communicating with the remaining sides of the header and depending therefrom, an ice tray sleeve enclosed by the ducts and secured thereto, and a control instrumentality disposed within the loop portion above said sleeve.

4. An evaporator comprising an elongated header whose extremities are connected to form a closed receptacle, suction and supply conduits communicating with the header at remotely spaced apart points in the header, whereby reirigerant admitted into the header through the supply conduit flows through two passages in the header in the direction of the suction conduit, and a plurality of depending duct elements each having its extremities communicating with opposed passages in the header.

LAWRENCE C. SMITH. 

